Shaping pulses using a multi-section optical load

ABSTRACT

An optical device may drive a compensation section of a multi-section optical load to emit a compensation optical pulse by providing, for a first time interval, a compensation electrical pulse to the compensation section. The optical device may drive a main section of the multi-section optical load to emit a main optical pulse by generating, for a second time interval, a main electrical pulse, wherein at least a portion of the first time interval overlaps with the second time interval. The optical device may emit a combined optical pulse, wherein the combined optical pulse includes the compensation optical pulse and the main optical pulse, and wherein the combined optical pulse has a shorter rise time than the main optical pulse.

RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/993,419, entitled “METHOD FOR SHAPING PULSES USING MULTI-SECTIONVERTICAL-CAVITY SURFACE-EMITTING LASER ARRAY,” filed on Mar. 23, 2020,and to U.S. Provisional Patent Application No. 62/993,234, entitled“RECONFIGURABLE LASER PULSE GENERATING CIRCUIT,” filed on Mar. 23, 2020,the contents of which are incorporated by reference herein in theirentirety.

TECHNICAL FIELD

The present disclosure relates generally to electrical drive circuitsfor optical loads and to methods and electrical drive circuits fordriving multi-section optical loads to emit rectangular-shaped opticalpulses.

BACKGROUND

Time-of-flight-based (TOF-based) measurement systems, such asthree-dimensional (3D) sensing systems, light detection and ranging(LIDAR) systems, and/or the like, emit optical pulses into a field ofview, detect reflected optical pulses, and determine distances toobjects in the field of view by measuring delays and/or differencesbetween the emitted optical pulses and the reflected optical pulses.

SUMMARY

According to some implementations, a method may include driving, by anelectrical drive circuit, a compensation section of the multi-sectionoptical load to emit a compensation optical pulse by providing, for afirst time interval, a compensation electrical pulse to the compensationsection; driving, by the electrical drive circuit, a main section of themulti-section optical load to emit a main optical pulse by generating,for a second time interval, a main electrical pulse, wherein at least aportion of the first time interval overlaps with the second timeinterval, wherein the compensation section and the main section areelectrically separate sections of the multi-section optical load, andproviding the main electrical pulse to the main section; and emitting,by an optical device including the electrical drive circuit and themulti-section optical load, a combined optical pulse, wherein thecombined optical pulse includes the compensation optical pulse and themain optical pulse, and wherein the combined optical pulse has a shorterrise time than the main optical pulse.

According to some implementations, an electrical drive circuit mayinclude a charging circuit path for charging, during a charging time,one or more inductive elements, a discharging circuit path forgenerating, during a first time interval after the charging time, acompensation electrical pulse by discharging the one or more inductiveelements, a main circuit path for generating, during a second timeinterval, a main electrical pulse, wherein at least a portion of thefirst time interval overlaps with the second time interval, and whereinthe electrical drive circuit is to provide a compensation electricalpulse to a compensation section of the multi-section optical load, andprovide a main electrical pulse to a main section of the multi-sectionoptical load, and wherein the compensation electrical pulse and the mainelectrical pulse are provided to the multi-section optical load viaindependent circuit paths.

According to some implementations, an optical device may include one ormore sources, a multi-section optical load to emit light, wherein themulti-section optical load includes a compensation section and a mainsection, and wherein the compensation section is electrically separatedfrom the main section within the multi-section optical load; acompensation circuit for generating a compensation electrical pulse andproviding the compensation electrical pulse to the compensation section,a main circuit for generating a main electrical pulse and providing themain electrical pulse to the main section, and a controller to controlthe compensation circuit and the main circuit by causing thecompensation circuit to generate the compensation electrical pulse for afirst time interval, and causing the main circuit to generate the mainelectrical pulse for a second time interval, wherein at least a portionof the first time interval overlaps with the second time interval, andwherein the compensation section is to emit, in response to thecompensation electrical pulse, a compensation optical pulse, wherein themain section is to emit, in response to the main electrical pulse, amain optical pulse, wherein a combined optical pulse includes thecompensation optical pulse and the main optical pulse, and wherein thecombined optical pulse has a shorter rise time than the main opticalpulse.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A, 1B, 2, and 3 are circuit diagrams of example implementationsof an electrical drive circuit and optical load described herein.

FIG. 4A is a diagram of an example implementation of a controller for anelectrical drive circuit described herein.

FIG. 4B is a diagram of an example implementation of a processimplemented by a controller for an electrical drive circuit describedherein.

FIG. 5 is a diagram of an example graph plotting voltages from anoptical detector receiving an optical signal associated with an exampleimplementation of an electrical drive circuit and optical load describedherein.

FIG. 6 is a diagram of an example graph plotting voltages from anoptical detector receiving an optical signal associated with an exampleimplementation of an electrical drive circuit and optical load describedherein.

FIG. 7 is a diagram of example graphs plotting switch timing in anexample implementation of an electrical drive circuit and amulti-section optical load, optical power of a section of themulti-section optical load, optical power of another section of themulti-section optical load, and optical power of the multi-sectionoptical load as seen by a sensor.

FIGS. 8A and 8B are diagrams of example graphs plotting shapes ofoptical power of a section of a multi-section optical load in exampleimplementations described herein.

FIGS. 9A and 9B are diagrams of example graphs plotting voltages from anoptical detector receiving optical signals associated with exampleimplementations of electrical drive circuits and optical loads describedherein.

FIGS. 10A, 10B, 10C, and 10D are diagrams of example implementations ofa multi-section optical load described herein.

FIG. 11 is a diagram of an example optical output field of view of anexample implementation of an electrical drive circuit and multi-sectionoptical load as described herein.

FIG. 12 is a flowchart of an example process for driving a multi-sectionoptical load.

DETAILED DESCRIPTION

The following detailed description of example implementations refers tothe accompanying drawings. The same reference numbers in differentdrawings may identify the same or similar elements.

TOF-based measurement systems may include an optical load (e.g., a laserdiode, a semiconductor laser diode, a vertical-cavity surface-emittinglaser (VCSEL), and/or the like) for emitting optical pulses into a fieldof view. As noted, TOF-based measurement systems may determine distancesto objects by measuring delays and/or differences between an emittedoptical pulse and a reflected optical pulse. TOF-based measurementsystems may perform direct time-of-flight (d-TOF) measurements and/orindirect time-of-flight (i-TOF) measurements. For d-TOF applications, anarrow optical pulse may be emitted into a field of view. For i-TOFapplications, a rectangular-shaped pulse train may be emitted into afield of view.

Emitting optical pulses having a well-defined origin in time and arectangular shape may improve measurement precision and accuracy (e.g.,as compared to optical pulses having a non-rectangular shape, a longrise time, and/or the like). To achieve such a rectangular shape, anemitted optical pulse should have a short rise time (e.g., a time duringwhich power of the optical pulse is rising) and a short fall time (e.g.,a time during which power of the optical pulse is falling). For example,the rise time of an optical pulse may be a time during which power ofthe optical pulse rises from 10% of peak power to 90% of peak power, andmay be referred to as a 10%-90% rise time. Similarly, the fall time ofan optical pulse may be a time during which power of the optical pulsefalls from 90% of peak power to 10% of peak power, and may be referredto as a 90%-10% fall time.

A circuit for driving an optical load is a set of electronic componentsinterconnected by current-carrying conductors (e.g., traces). Any of theelectronic components and conductors may have parasitic elements (e.g.,a parasitic inductance, a parasitic resistance, and/or a parasiticcapacitance). These parasitic elements may be undesirable, and,therefore, sought to be minimized. However, completely eliminating theseparasitic elements may not be possible (e.g., due to manufacturabilitylimitations, component size limitations, and/or the like). When a supplyvoltage is provided to the circuit to drive the optical load, theparasitic inductance, the parasitic resistance, and/or the parasiticcapacitance in the circuit cause a delay between when the supply voltageis provided and when a current reaches a peak. The delay increases therise time of the electrical pulse, which increases the rise time of theoptical pulse (e.g., particularly when the circuit drives the opticalload with a high current).

Some implementations described herein provide a method and/or anelectrical drive circuit for driving a multi-section optical load toemit a rectangular-shaped optical pulse and/or a pulse train ofrectangular-shaped optical pulses. For example, the method and/or theelectrical drive circuit may drive the multi-section optical load toemit an optical pulse having a short rise time (e.g., less than 100picoseconds (ps)), a short fall time (e.g., less than 500 ps, less than300 ps, and/or the like) and/or a constant amplitude. Someimplementations described herein provide a method and/or an electricaldrive circuit including one or more circuit paths for driving twosections of a multi-section optical load to each emit an optical pulse,and combining the emitted optical pulses in an optical domain to achievea combined optical pulse having a rectangular shape.

In some implementations, the method and/or the electrical drive circuitmay drive a compensation section of a multi-section optical load to emita compensation optical pulse. For example, in some implementations, thecompensation section may be driven to emit the compensation opticalpulse by charging one or more inductive elements and discharging, afterthe charging and for a first time interval, the one or more inductiveelements to provide a compensation electrical pulse to the compensationsection. Additionally, or alternatively, the method and/or theelectrical drive circuit may drive a main section of the multi-sectionoptical load to emit a main optical pulse by generating, after thecharging and for a second time interval, a main electrical pulse, whereat least a portion of the first time interval overlaps with the secondtime interval, and providing the main electrical pulse to the mainsection. In some implementations, the multi-section optical load mayemit a combined optical pulse including the compensation optical pulseand the main optical pulse, where the combined optical pulse has ashorter rise time than the main optical pulse. For example, the mainoptical pulse may have a longer rise time as compared to thecompensation optical pulse, and a shorter rise time of the compensationoptical pulse may compensate for the longer rise time of the mainoptical pulse.

In this way, the method and/or the electrical drive circuit may drivethe multi-section optical load to emit a rectangular-shaped opticalpulse and/or a pulse train of rectangular-shaped optical pulses. Bydriving the multi-section optical load to emit a rectangular-shapedoptical pulse and/or a pulse train of rectangular-shaped optical pulses,the method and/or the electrical drive circuit may improve performanceof a time-of-flight-based measurement system.

FIG. 1A is a circuit diagram of an example implementation 100 of anelectrical drive circuit and a multi-section optical load 140 describedherein. As shown in FIG. 1A, an optical device may include a chargingcircuit path 102, a discharging circuit path 104, and a main circuitpath 106. In some implementations and as described further herein, thecharging circuit path 102 and the discharging circuit path 104 may beused to generate a compensation electrical pulse to drive a compensationsection 118, of the multi-section optical load 140, to emit acompensation optical pulse. Additionally, or alternatively, and asdescribed further herein, the main circuit path 106 may be used togenerate a main electrical pulse to drive a main section 128, of themulti-section optical load 140, to emit a main optical pulse.

As shown in FIG. 1A, the optical device may further include acompensation source 108, a compensation capacitive element 110, acompensation inductive element 112, a compensation switch 114, ablocking capacitive element 116, the compensation section 118 of themulti-section optical load 140, inductive elements 120 and 122, a mainsource 124, a main capacitive element 126, the main section 128 of themulti-section optical load 140, a main switch 130, inductive elements132 and 134, a main ground 136, a compensation ground 138, and themulti-section optical load 140. In some implementations, the electricaldrive circuit may include the charging circuit path 102, the dischargingcircuit path 104, the main circuit path 106, the compensation capacitiveelement 110, the compensation inductive element 112, the compensationswitch 114, the blocking capacitive element 116, the inductive elements120 and 122, the main capacitive element 126, the main switch 130, theinductive elements 132 and 134, the main ground 136, and thecompensation ground 138. In some implementations, and as shown in FIG.1A, the electrical drive circuit may include multiple electricalcircuits (e.g., a compensation circuit and/or a compensation circuitpath, including the charging circuit path 102 and the dischargingcircuit path 104, and a main circuit including the main circuit path106).

In some implementations, the main electrical pulse and/or thecompensation electrical pulse may also be referred to as a firstelectrical pulse, a second electrical pulse, and/or the like. Similarly,the main optical pulse and/or the compensation optical pulse may also bereferred to as a first optical pulse, a second optical pulse, and/or thelike. Additionally, or alternatively, the charging circuit path 102, thedischarging circuit path 104, and/or the main circuit path 106 may alsobe referred to as a first circuit path, a second circuit path, a thirdcircuit path, and/or the like. Additionally, or alternatively, thecompensation capacitive element 110, the blocking capacitive element116, and/or the main capacitive element 126 may also be referred to as afirst capacitive element, a second capacitive element, a thirdcapacitive element, and/or the like. In this regard, adjectives such as“main,” “charging,” “discharging,” “compensation,” and “blocking” areused herein for descriptive purposes and not to limit the scope of theelements, components, and/or the like which they modify, unlessexplicitly stated otherwise.

As shown in FIG. 1A, the charging circuit path 102 may be connected tothe compensation source 108, and may include the compensation capacitiveelement 110, the compensation inductive element 112, and thecompensation switch 114. The discharging circuit path 104 may beconnected to the compensation source 108 and the compensation section118, and may include the compensation capacitive element 110, thecompensation inductive element 112, the blocking capacitive element 116,and the inductive elements 120 and 122. The main circuit path 106 may beconnected to the main source 124 and the main section 128, and mayinclude the main capacitive element 126, the main switch 130, and theinductive elements 132 and 134.

In some implementations, the compensation source 108 and/or the mainsource 124 may provide current to the electrical drive circuit. Forexample, the compensation source 108 and/or the main source 124 may be adirect current (DC) voltage source, a DC current source with a resistiveload, and/or the like.

In some implementations, the compensation source 108 (e.g., a voltagesource) may affect pulse height and/or width (e.g., amplitude and/orduration) of the compensation electrical pulse, which may affect pulseheight and/or width (e.g., amplitude and/or duration) of thecompensation optical pulse from the compensation section 118. Forexample, with increased voltage in the compensation source 108, thecompensation electrical pulse and/or the compensation optical pulse maybecome larger and/or wider (e.g., increased amplitude and/or increasedtime duration). In some implementations, compensation current issupplied from the compensation capacitive element 110 (e.g., to thecompensation section 118), and, as the voltage of the compensationsource 108 increases, fall time of the compensation electrical pulseand/or the compensation optical pulse may increase.

In some implementations, the compensation capacitive element 110 mayinclude one or more capacitors (e.g., of compensation circuitry). Insome implementations, the compensation capacitive element 110 may bereferred to as a decoupling capacitor that may provide a surge current(e.g., during a duration of the compensation electrical pulse).Additionally, or alternatively, the compensation capacitive element 110may have a low equivalent serial inductance (ESL).

In some implementations, the compensation inductive element 112 mayinclude one or more inductive elements, and/or may model a totalinductance of the charging circuit path 102 and/or the dischargingcircuit path 104. For example, the compensation inductive element 112may model inductances of current-carrying conductors in the electricaldrive circuit, bond wires in the electrical drive circuit, and/or thelike.

In some implementations, the compensation inductive element 112 mayinclude a trace (e.g., a circuit trace on a printed circuit board (PCB),a wire trace, a track, and/or the like) having a length and/or a widthbased on required total inductance taking into account parasiticinductance of other circuit elements (e.g., current-carrying conductorsin the electrical drive circuit, bond wires in the electrical drivecircuit, and/or the like). In some implementations, the trace may have alength and/or a width to achieve a total inductance for the electricaldrive circuit, the charging circuit path 102, and/or the dischargingcircuit path 104. For example, the trace may be designed (e.g., have alength, have a width, and/or the like) to add inductance to theelectrical drive circuit, the charging circuit path 102, and/or thedischarging circuit path 104, thereby increasing the total inductancefor the electrical drive circuit, the charging circuit path 102, and/orthe discharging circuit path 104.

Additionally, or alternatively, and as described further herein, aninductance of the compensation inductive element 112 and/or the totalinductance of the electrical drive circuit, the charging circuit path102, and/or the discharging circuit path 104 may be selected,controlled, adjusted, and/or the like such that a fall time of thecompensation optical pulse corresponds to a rise time of the mainoptical pulse, which may facilitate driving the multi-section opticalload 140 to emit a rectangular-shaped optical pulse (e.g., asquare-shaped optical pulse). For example, the compensation inductiveelement 112 may include a trace having a length and/or a width toachieve, for the electrical drive circuit, the charging circuit path102, and/or the discharging circuit path 104, a total inductance suchthat the compensation optical pulse, emitted in response to thecompensation electrical pulse, has a width and/or an amplitude thatcompensates the main optical pulse.

In some implementations, the compensation switch 114 and/or the mainswitch 130 may be a high speed and low output capacitance switch. Forexample, the compensation switch 114 and/or the main switch 130 may be atransistor, such as a field effect transistor (FET), a metal-oxidesemiconductor field-effect transistor (MOSFET), a Gallium Nitridefield-effect transistor (GaNFET), an avalanche transistor, and/or thelike. In some implementations, the compensation capacitive element 110may model, at least in part, a capacitance of the compensation switch114, and the main capacitive element 126 may model, at least in part, acapacitance of the main switch 130. In some implementations, thecompensation switch 114 may have a low inductance (e.g., to facilitateachieving a short rise time of the compensation electrical pulse and/orthe compensation optical pulse).

In some implementations, the blocking capacitive element 116 may be ablocking capacitor, and the compensation section 118 may bealternating-current-coupled (AC-coupled). For example, the blockingcapacitive element 116 may be a blocking capacitor preventing thecompensation section 118 from emitting light when the compensationswitch 114 is in a closed state. In such an example, the compensationsource 108 may provide an input (e.g., a voltage, a current, and/or thelike), where the input is greater than a threshold at which thecompensation section 118 emits light (e.g., a laser threshold voltageand/or the like). By providing an input greater than the threshold atwhich the compensation section 118 emits light, the compensation source108 may charge the compensation inductive element 112 with a greateramount of energy in a shorter amount of time than if the input waslimited by the threshold at which the compensation section 118 emitslight. If the blocking capacitive element 116, acting as a blockingcapacitor, were absent, the compensation source 108 may eitherundesirably cause the compensation section 118 to emit light when thecompensation switch 114 was closed (e.g., if the input was greater thanthe threshold of the compensation section 118), or the compensationsource 108 may be limited to providing an input lower than the thresholdof the compensation section 118, undesirably decreasing the amount ofenergy and/or amount of time for charging the compensation inductiveelement 112.

In some implementations, the inductive elements 120 and 122 may modelparasitic inductances of current-carrying conductors in the electricaldrive circuit, the discharging circuit path 104, and/or themulti-section optical load 140. Additionally, or alternatively, theinductive elements 120 and 122 may model parasitic inductances of bondwires in the electrical drive circuit, the discharging circuit path 104,and/or the multi-section optical load 140.

In some implementations, the main capacitive element 126 may be avoltage storage element, and may provide a surge current (e.g., during aduration of the main electrical pulse). Additionally, or alternatively,the main capacitive element 126 may include one or more capacitors.

In some implementations, the inductive elements 132 and 134 may modelparasitic inductances of current-carrying conductors in the electricaldrive circuit, the main circuit path 106, and/or the multi-sectionoptical load 140. Additionally, or alternatively, the inductive elements132 and 134 may model parasitic inductances of bond wires in theelectrical drive circuit, the main circuit path 106, and/or themulti-section optical load 140.

In some implementations, the multi-section optical load 140 may includean array of one or more light-emitting diodes, an array of one or morelaser diodes, an array of one or more semiconductor laser diodes, anarray of one or more vertical-cavity surface-emitting lasers (VCSELs),and/or the like. In some implementations, the multi-section optical load140 may comprise multiple optical loads electrically connected inparallel and/or in series. For example, the multi-section optical load140 may include a VCSEL array with 400 emitters electrically connectedin parallel. As another example, the multi-section optical load 140 mayinclude multiple VCSELs (e.g., arrays or singlets) connected in series(e.g., on a printed circuit board (PCB)), which may provide increasedoptical power as compared to a single VCSEL array. In someimplementations, as shown in FIG. 1A, the multi-section optical load 140includes multiple sections that are electrically independent andconnected to different circuits. For example, a first section of themulti-section optical load 140 may include the compensation section 118and inductive elements 120 and 122, which are connected to thecompensation circuit and/or compensation circuit path that includes thecharging circuit path 102 and the discharging circuit path 104. Asfurther shown in FIG. 1A, a second section of the multi-section opticalload 140 may include the main section 128 and inductive elements 132 and134, which are connected to the main circuit that includes the maincircuit path 106. Accordingly, as described herein, the first sectionand the second section may be electrically separate sections of themulti-section optical load 140. However, it will be appreciated that, insome implementations, different sections of the multi-section opticalload 140 may be electrically connected via other circuits (e.g., theelectrical drive circuit).

As noted above, the multi-section optical load 140 may include thecompensation section 118 and the main section 128. In someimplementations, the multi-section optical load 140 may be a VCSEL arraydie (e.g., a die including an array of VCSELs), and each of thecompensation section 118 and the main section 128 may be a section ofthe VCSEL array die. For example, the compensation section 118 mayinclude a first set of VCSELs on the VCSEL array die, and the mainsection 128 may include a second set of VCSELs on the VCSEL array die.In some implementations, the compensation section 118 and the mainsection 128 may be adjacent to each other on the VCSEL array die, suchthat the first set of VCSELs of the compensation section 118 is adjacentto the second set of VCSELs of the main section 128.

Additionally, or alternatively, the compensation section 118 and themain section 128 may be interleaved on the VCSEL array die, such thatthe first set of VCSELs of the compensation section 118 are interspersedwithin the second set of VCSELs of the main section 128 and/or such thatthe second set of VCSELs of the main section 128 are interspersed withinthe first set of VCSELs of the compensation section 118. For example,the first set of VCSELs of the compensation section 118 and the secondset of VCSELs of the main section 128 may be alternating rows of VCSELson the VCSEL array die. Additionally, or alternatively, the first set ofVCSELs of the compensation section 118 and/or the second set of VCSELsof the main section 128 may be positioned in a pattern (e.g., a regularpattern, a pseudo-random pattern, and/or the like), a shape (e.g., arectangle, a square, a circle, and/or the like), and/or the like.

In some implementations, the multi-section optical load 140 may be apackage of VCSEL array dies (e.g., placed in a same substrate and/or thelike), and each of the compensation section 118 and the main section 128may be a VCSEL array die of the package. For example, the compensationsection 118 may include a first VCSEL array die of the package, and themain section 128 may include a second VCSEL array die of the package.

In some implementations, the multi-section optical load 140 maygenerally include multiple sections, and the electrical drive circuitmay be a multi-channel electrical drive circuit in which each section ofthe multi-section optical load 140 is controlled by a different channelof the multi-channel electrical drive circuit. For example, themulti-section optical load 140 may include six sections, the electricaldrive circuit may be a six-channel electrical drive circuit, and eachsection of the multi-section optical load 140 may be controlled by adifferent channel of the six-channel electrical drive circuit.Additionally, or alternatively, each section may include a same quantityof VCSELs, different quantities of VCSELs, and/or the like. In this way,a quantity of VCSELs driven by the electrical drive circuit to emit anoptical pulse at a given time may be controlled, for example, such thatthe multi-section optical load 140 emits a rectangular-shaped opticalpulse.

As noted above, the main circuit path 106 may be used to generate a mainelectrical pulse to drive the main section 128, of the multi-sectionoptical load 140, to emit the main optical pulse. The main switch 130may have an open state (e.g., an off state), where, when the main switch130 is in the open state, current may not flow through the main switch130. In some implementations, when the main switch 130 is in the openstate, current may not flow through the main section 128. The mainswitch 130 may also have a closed state (e.g., an on state), where, whenthe main switch 130 is in the closed state, current may flow through themain switch 130. In some implementations, when the main switch 130 is inthe closed state, current may flow through the main circuit path 106 andgenerate the main electrical pulse to drive the main section 128 to emitthe main optical pulse. The electrical drive circuit may provide themain electrical pulse to the main section 128. In some implementations,and as described further herein, the main section 128 may emit, based onthe main electrical pulse, a main optical pulse with a slow rise time(e.g., a long rise time) similar to an optical pulse shown and describedherein with respect to FIG. 6.

As shown in FIG. 1A, the main capacitive element 126 (e.g., a voltagestorage capacitive element) may be connected in parallel to the mainsource 124. In some implementations, because the main capacitive element126 is connected closer to the multi-section optical load 140 than themain source 124, when the main switch 130 transitions from the openstate to the closed state, current may flow through the main capacitiveelement 126 of the main circuit path 106 more immediately than throughthe main source 124.

In some implementations, an input (e.g., a voltage, a current, and/orthe like) provided by the main source 124 may be controlled to adjustcharacteristics of the main electrical pulse and/or the main opticalpulse. For example, a higher voltage provided by the main source 124 mayincrease a maximum amplitude of the main electrical pulse and/or themain optical pulse as compared to another maximum amplitude of the mainelectrical pulse and/or the main optical pulse when a lower voltage isprovided by the main source 124. As another example, a higher voltageprovided by the main source 124 may reduce a rise time of the mainelectrical pulse and/or the main optical pulse as compared to anotherrise time of the main electrical pulse and/or the main optical pulsewhen a lower voltage is provided by the main source 124.

As noted above, the charging circuit path 102 and the dischargingcircuit path 104 may be used to generate a compensation electrical pulseto drive a compensation section 118, of the multi-section optical load140, to emit a compensation optical pulse. The compensation switch 114may have an open state (e.g., an off state), where, when thecompensation switch 114 is in the open state, current may not flowthrough the compensation switch 114. Additionally, the compensationswitch 114 may have a closed state (e.g., an on state), where, when thecompensation switch 114 is in the closed state, current may flow throughthe compensation switch 114. In some implementations, when thecompensation switch 114 is in the closed state, current charges thecompensation inductive element 112 (e.g., including one or moreparasitic elements in the electrical drive circuit) through the chargingcircuit path 102. For example, when the compensation switch 114 is inthe closed state, current may flow through the compensation switch 114and charge (e.g., during a charging time) the compensation inductiveelement 112 (e.g., including one or more parasitic elements in thedriver circuit) through the charging circuit path 102.

In some implementations, when the compensation switch 114 transitionsfrom the closed state to the open state, current may not flow throughthe compensation switch 114, and current may discharge from thecompensation inductive element 112 (e.g., as well as one or moreparasitic elements in the electrical drive circuit) through thedischarging circuit path 104 and generate a compensation electricalpulse to drive the compensation section 118 to emit a compensationoptical pulse. For example, when the compensation switch 114 transitionsfrom the closed state to the open state, current may not flow throughthe compensation switch 114, and current may discharge, during adischarge time, from the compensation inductive element 112 (e.g., aswell as one or more parasitic elements in the electrical drive circuit)through the discharging circuit path 104.

As shown in FIG. 1A, the compensation capacitive element 110 (e.g., avoltage storage capacitive element) may be connected in parallel to thecompensation source 108, and the compensation capacitive element 110 maybe closer (e.g., in a practical sense) to the compensation inductiveelement 112 and the compensation section 118 than the compensationsource 108. In some implementations, the compensation capacitive element110 may provide a faster current change than the compensation source108. For example, the compensation source 108 may have a largeinductance in a path between the compensation source 108 and thecompensation inductive element 112, which may prevent the compensationsource 108 from providing a fast current change. In someimplementations, a majority (e.g., almost 100%) of the currentdischarged through discharging circuit path 104 may be provided by thecompensation capacitive element 110 (e.g., which may be slowly chargedby the compensation source 108 before the compensation switch 114transitions from the closed state to the open state).

In some implementations, an input (e.g., a voltage, a current, and/orthe like) provided by the compensation source 108 may be controlled toadjust characteristics of the compensation electrical pulse and/or thecompensation optical pulse. For example, a higher voltage provided bythe compensation source 108 may increase a maximum amplitude of thecompensation electrical pulse and/or the compensation optical pulse ascompared to another maximum amplitude of the compensation electricalpulse and/or the compensation optical pulse when a lower voltage isprovided by the compensation source 108. As another example, a highervoltage provided by the compensation source 108 may reduce a chargingtime of the compensation inductive element 112 as compared to anothercharging time of the compensation inductive element 112 when a lowervoltage is provided by the compensation source 108. In someimplementations, and as noted above, a capacitance of the compensationcapacitive element 110 may affect pulse height and/or width (e.g.,amplitude and/or duration) of the compensation electrical pulse and/orthe compensation optical pulse.

Additionally, or alternatively, an inductance of the compensationinductive element 112 may be controlled to adjust characteristics of thecompensation electrical pulse and/or the compensation optical pulse. Forexample, a higher inductance of the compensation inductive element 112may increase a fall time of the compensation electrical pulse and/or thecompensation optical pulse as compared to another fall time of thecompensation electrical pulse and/or the compensation optical pulse whenthe compensation inductive element 112 has a lower inductance. In someimplementations, and as further described herein with respect to FIGS.8A and 8B, the inductance of the compensation inductive element 112 maybe selected, controlled, adjusted, and/or the like such that a fall timeof the compensation optical pulse corresponds to a rise time of the mainoptical pulse, which may facilitate driving the multi-section opticalload 140 to emit a rectangular-shaped optical pulse.

The electrical drive circuit may provide the compensation electricalpulse to the compensation section 118. In some implementations, and asdescribed further herein, the compensation section 118 may emit, basedon the compensation electrical pulse, a compensation optical pulse witha short rise time (e.g., a fast rise time) similar to an optical pulseshown and described herein with respect to FIG. 5.

In some implementations, and as described further herein with respect toFIGS. 4A, 4B, 7, 8A, 8B, 9A, and 9B, a timing of the main switch 130 andthe compensation switch 114 may be controlled (e.g., by a controller)such that the electrical drive circuit generates the main electricalpulse and the compensation electrical pulse, provides the mainelectrical pulse to the main section 128 to drive the main section 128to emit the main optical pulse, and provides the compensation electricalpulse to the compensation section 118 to drive the compensation section118 to emit the compensation optical pulse. For example, the timing ofthe main switch 130 and the compensation switch 114 may be controlledsuch that the compensation electrical pulse is discharged during adischarge time that at least partially overlaps with a time intervalduring which the main electrical pulse is generated. Additionally, oralternatively, the timing of the main switch 130 and the compensationswitch 114 may be controlled such that a fall time of the compensationelectrical pulse and/or the compensation optical pulse corresponds to arise time of the main electrical pulse and/or the main optical pulse.Furthermore, the timing of the main switch 130 and the compensationswitch 114 may be controlled such that a combined optical pulse,including the compensation optical pulse and the main optical pulse, hasa rise time proportional to a rise time of the compensation opticalpulse. Additionally, or alternatively, the timing of the main switch 130and the compensation switch 114 may be controlled such that the combinedoptical pulse has a shorter fall time than the compensation opticalpulse.

As indicated above, FIG. 1A is provided merely as an example. Otherexamples may differ from what is described with regard to FIG. 1A.

FIG. 1B is a circuit diagram of an example implementation 150 of anelectrical drive circuit and a multi-section optical load 190 describedherein. Example implementation 150 may be similar to exampleimplementation 100 described herein with respect to FIG. 1A, but inexample implementation 150, the compensation circuit may not include thecharging circuit path 102, the compensation inductive element 112, theblocking capacitive element 116, and/or the like. Furthermore, inexample implementation 150, the compensation circuit may include acompensation switch 164 in series with a compensation section 168 of themulti-section optical load 190. For example, and as shown in FIG. 1B, anoptical device may include a compensation circuit path 154 provided inthe compensation circuit and a main circuit path 156 provided in themain circuit.

In some implementations, the electrical drive circuit (e.g., via thecompensation circuit path 154) may provide a current of a few hundredsof milliamps (mA) (e.g., a current in a range from about 200 mA to 500mA, such as 300 mA, 350 mA, 400 mA, and/or the like) to the compensationsection 168. Additionally, or alternatively, in such an implementation,the electrical drive circuit may use a different switch timing in whichthe compensation switch 164 in series with the compensation section 168and the main switch 180 turn on (e.g., transition from an open state toa closed state) at approximately the same time.

In some implementations, the compensation circuit path 154 and the maincircuit path 156 may be similar to the discharging circuit path 104 andthe main circuit path 106, respectively, as described herein withrespect to example implementation 100 and FIG. 1A. For example, when thecompensation switch 164 is in the closed state, current may flow throughthe compensation circuit path 154, which may generate a compensationelectrical pulse to drive the compensation section 168, of themulti-section optical load 190, to emit a compensation optical pulse.Similarly, when the main switch 180 is in the closed state, current mayflow through the main circuit path 156 to generate a main electricalpulse to drive a main section 178, of the multi-section optical load190, to emit a main optical pulse.

As shown in FIG. 1B, the optical device may further include acompensation source 158, a compensation capacitive element 160, thecompensation section 168 of the multi-section optical load 190,inductive elements 170 and 172, a main capacitive element 176, the mainsection 178 of the multi-section optical load 190, a main switch 180,inductive elements 182 and 184, a main ground 186, a compensation ground188, and the multi-section optical load 190. In some implementations,the electrical drive circuit may include the compensation circuit path154, the main circuit path 156, the compensation capacitive element 160,the compensation switch 164, the inductive elements 170 and 172, themain capacitive element 176, the main switch 180, the inductive elements182 and 184, the main ground 186, and the compensation ground 188.

In some implementations, the compensation source 158, the compensationcapacitive element 160, the compensation switch 164, the compensationsection 168, the inductive elements 170 and 172, the main capacitiveelement 176, the main section 178, the main switch 180, the inductiveelements 182 and 184, and the multi-section optical load 190 may besimilar to the compensation source 108, the compensation capacitiveelement 110, the compensation switch 114, the compensation section 118,the inductive elements 120 and 122, the main capacitive element 126, themain section 128, the main switch 130, the inductive elements 132 and134, and the multi-section optical load 140, respectively, as describedherein with respect to example implementation 100 and FIG. 1A.

As indicated above, FIG. 1B is provided merely as an example. Otherexamples may differ from what is described with regard to FIG. 1B.

FIG. 2 is a circuit diagram of an example implementation 200 of anelectrical drive circuit and a multi-section optical load 240 describedherein. Example implementation 200 may be similar to exampleimplementation 100 described herein with respect to FIG. 1A, but exampleimplementation 200 may not include the main source 124 of exampleimplementation 100. For example, and as shown in FIG. 2, an opticaldevice may include a charging circuit path 202, a discharging circuitpath 204, and a main circuit path 206 that are connected to acompensation source 208 (e.g., a single source).

In some implementations, the charging circuit path 202, the dischargingcircuit path 204, and the main circuit path 206 may be similar to thecharging circuit path 102, the discharging circuit path 104, and themain circuit path 106, respectively, as described herein with respect toexample implementation 100 and FIG. 1A. For example, the chargingcircuit path 202 and the discharging circuit path 204 may be used togenerate a compensation electrical pulse to drive a compensation section218, of the multi-section optical load 240, to emit a compensationoptical pulse, and the main circuit path 206 may be used to generate amain electrical pulse to drive a main section 228, of the multi-sectionoptical load 240, to emit a main optical pulse. In some implementations,a compensation circuit and/or a compensation circuit path may includethe charging circuit path 202 and the discharging circuit path 204.

As shown in FIG. 2, the optical device may further include acompensation source 208, a compensation capacitive element 210, acompensation inductive element 212, a compensation switch 214, ablocking capacitive element 216, the compensation section 218 of themulti-section optical load 240, inductive elements 220 and 222, a maincapacitive element 226, the main section 228 of the multi-sectionoptical load 240, a main switch 230, inductive elements 232 and 234, acompensation ground 236, and the multi-section optical load 240. In someimplementations, the electrical drive circuit may include the chargingcircuit path 202, the discharging circuit path 204, the main circuitpath 206, the compensation capacitive element 210, the compensationinductive element 212, the compensation switch 214, the blockingcapacitive element 216, the inductive elements 220 and 222, the maincapacitive element 226, the main switch 230, the inductive elements 232and 234, and the compensation ground 236.

In some implementations, the compensation source 208, the compensationcapacitive element 210, the compensation inductive element 212, thecompensation switch 214, the blocking capacitive element 216, thecompensation section 218, the inductive elements 220 and 222, the maincapacitive element 226, the main section 228, the main switch 230, theinductive elements 232 and 234, and the multi-section optical load 240may be similar to the compensation source 108, the compensationcapacitive element 110, the compensation inductive element 112, thecompensation switch 114, the blocking capacitive element 116, thecompensation section 118, the inductive elements 120 and 122, the maincapacitive element 126, the main section 128, the main switch 130, theinductive elements 132 and 134, and the multi-section optical load 140,respectively, as described herein with respect to example implementation100 and FIG. 1A.

In some implementations, an input (e.g., a voltage, a current, and/orthe like) provided by the compensation source 208 may be controlled toadjust characteristics of the main electrical pulse and/or the mainoptical pulse in a manner similar to that described herein with respectto controlling an input provided by the main source 124 as describedwith respect to example implementation 100 and FIG. 1A. In other words,rather than controlling input provided by a main source to adjustcharacteristics of the main electrical pulse and/or the main opticalpulse, in the example implementation 200 of FIG. 2, the input of thecompensation source 208 may be controlled to adjust characteristics ofthe main electrical pulse and/or the main optical pulse. Additionally,or alternatively, the electrical drive circuit of example implementation200 and/or a timing of the main switch 230 and the compensation switch214 may be controlled (e.g., by a controller) in a manner similar tothat described herein with respect to example implementation 100 andFIG. 1A.

As indicated above, FIG. 2 is provided merely as an example. Otherexamples may differ from what is described with regard to FIG. 2.

FIG. 3 is a circuit diagram of an example implementation 300 of anelectrical drive circuit and a multi-section optical load 340 describedherein. Example implementation 300 may be similar to exampleimplementation 100 described herein with respect to FIG. 1A, but exampleimplementation 300 may not include the main source 124 or the maincapacitive element 126 of example implementation 100. For example, andas shown in FIG. 2, an optical device may include a charging circuitpath 302, a discharging circuit path 304, and a main circuit path 306that are connected to a compensation source 308 (e.g., a single source)and include (e.g., share) a compensation capacitive element 310.

In some implementations, the charging circuit path 302, the dischargingcircuit path 304, and the main circuit path 306 may be similar to thecharging circuit path 102, the discharging circuit path 104, and themain circuit path 106, respectively, as described herein with respect toexample implementation 100 and FIG. 1A. For example, the chargingcircuit path 302 and the discharging circuit path 304 may be used togenerate a compensation electrical pulse to drive a compensation section318, of the multi-section optical load 340, to emit a compensationoptical pulse, and the main circuit path 306 may be used to generate amain electrical pulse to drive a main section 328, of the multi-sectionoptical load 340, to emit a main optical pulse. In some implementations,a compensation circuit and/or a compensation circuit path may includethe charging circuit path 302 and the discharging circuit path 304.

As shown in FIG. 3, the optical device may further include acompensation source 308, a compensation capacitive element 310, acompensation inductive element 312, a compensation switch 314, ablocking capacitive element 316, the compensation section 318 of themulti-section optical load 340, inductive elements 320 and 322, the mainsection 328 of the multi-section optical load 340, a main switch 330,inductive elements 332 and 334, a compensation ground 336, and themulti-section optical load 340. In some implementations, the electricaldrive circuit may include the charging circuit path 302, the dischargingcircuit path 304, the main circuit path 306, the compensation capacitiveelement 310, the compensation inductive element 312, the compensationswitch 314, the blocking capacitive element 316, the inductive elements320 and 322, the main switch 330, the inductive elements 332 and 334,and the compensation ground 336.

In some implementations, the compensation source 308, the compensationcapacitive element 310, the compensation inductive element 312, thecompensation switch 314, the blocking capacitive element 316, thecompensation section 318, the inductive elements 320 and 322, the mainsection 328, the main switch 330, the inductive elements 332 and 334,and the multi-section optical load 340 may be similar to thecompensation source 108, the compensation capacitive element 110, thecompensation inductive element 112, the compensation switch 114, theblocking capacitive element 116, the compensation section 118, theinductive elements 120 and 122, the main section 128, the main switch130, the inductive elements 132 and 134, and the multi-section opticalload 140, respectively, as described herein with respect to exampleimplementation 100 and FIG. 1A.

In some implementations, an input (e.g., a voltage, a current, and/orthe like) provided by the compensation source 308 may be controlled toadjust characteristics of the main electrical pulse and/or the mainoptical pulse in a manner similar to that described herein with respectto controlling an input provided by the main source 124 as describedwith respect to example implementation 100 and FIG. 1A. In other words,rather than controlling input provided by a main source to adjustcharacteristics of the main electrical pulse and/or the main opticalpulse, in the example implementation 300 of FIG. 3 the input of thecompensation source 308 may be controlled to adjust characteristics ofthe main electrical pulse and/or the main optical pulse.

In some implementations, the compensation capacitive element 310 mayaffect pulse height and/or width (e.g., amplitude and/or duration) ofthe main electrical pulse and/or the main optical pulse in a mannersimilar to that described herein with respect to the main capacitiveelement 126 affecting pulse height and/or width of the main electricalpulse and/or the main optical pulse. In other words, rather than acapacitance of a main capacitive element affecting pulse height and/orwidth of the main electrical pulse and/or the main optical pulse, in theexample implementation 300 of FIG. 3, a capacitance of the compensationcapacitive element 310 may affect pulse height and/or width of the mainelectrical pulse and/or the main optical pulse.

Additionally, or alternatively, the electrical drive circuit of exampleimplementation 300 and/or a timing of the main switch 330 and thecompensation switch 314 may be controlled (e.g., by a controller) in amanner similar to that described herein with respect to exampleimplementation 100 and FIG. 1A.

As indicated above, FIG. 3 is provided merely as an example. Otherexamples may differ from what is described with regard to FIG. 3.

FIG. 4A is a diagram of an example implementation 400 of a controller402 for an electrical drive circuit described herein. As shown in FIG.4A, the example implementation 400 may include the controller 402, amain gate driver 404, a compensation gate driver 406, a main switch 408,and a compensation switch 410. In some implementations, an integratedcircuit may include the controller 402, the main gate driver 404, thecompensation gate driver 406, the main switch 408, the compensationswitch 410, and/or the like.

Additionally, or alternatively, the main switch 408 and the compensationswitch 410 may be similar to the main switch 130 and the compensationswitch 114, respectively, as described herein with respect to exampleimplementation 100 and FIG. 1A, the main switch 180 and the compensationswitch 164, respectively, as described herein with respect to exampleimplementation 150 and FIG. 1B, and/or the like. Furthermore, the mainswitch 408 and the compensation switch 410 may, respectively, correspondto main switches (e.g., the main switch 130 of FIG. 1A, the main switch180 of FIG. 1B, the main switch 230 of FIG. 2, the main switch 330 ofFIG. 3, and/or the like) and compensation switches (e.g., thecompensation switch 114 of FIG. 1A, the compensation switch 164 of FIG.1B, the compensation switch 214 of FIG. 2, the compensation switch 314of FIG. 3, and/or the like) in the example implementations 100, 200, and300. In other words, example implementation 400 and controller 402 maybe used to control main switches and compensation switches for theelectrical drive circuits described herein with respect to FIGS. 1A, 1B,2, and/or 3. For example, as described above, FIGS. 1A and 1B relate todesigns that use two independent voltage sources (e.g., compensationsource 108 and main source 124, compensation source 158 and main source174, and/or the like), each having a capacitor (e.g., compensationcapacitive element 110 and main capacitive element 126, compensationcapacitive element 160 and main capacitive element 176, and/or thelike), which generally provides a flexible configuration. In some cases,however, where the two independent voltage sources require the samevoltage, the circuit can be simplified to reduce a bill of materials(BOM) cost. For example, as shown in FIG. 2, the circuit may use onlyone DC source but two capacitors, each of which is placed close to theanode of an optical load. Additionally, or alternatively, as shown inFIG. 3, two optical loads can share a single voltage source and a singlecapacitor to further reduce the BOM cost with a minor performance costrelative to the designs shown in FIGS. 1A, 1B, and 2. Accordingly, asthe various designs illustrated in FIGS. 1A, 1B, 2, 3 generally operatein a similar manner (e.g., by providing a compensation electrical pulseto a compensation section for a first time interval and generating amain electrical pulse for a second time interval that at least partiallyoverlaps with the second time interval), example implementation 400 andcontroller 402 may be used to control main switches and compensationswitches for any of the electrical drive circuits described herein withrespect to FIGS. 1A, 1B, 2, and/or 3.

FIG. 4B is a diagram of an example implementation 450 of a processimplemented by the controller 402 for an electrical drive circuitdescribed herein. As shown in FIG. 4B, the controller 402 may receive alaser pulse input (logic level) (e.g., a logic input signal), which maysignal that an optical load (e.g., the multi-section optical load 140 ofFIG. 1A, the multi-section optical load 240 of FIG. 2, the multi-sectionoptical load 340 of FIG. 3, and/or the like) driven by the electricaldrive circuit should turn on. The controller 402 may, based on the laserpulse input, generate control signals (e.g., voltages) for the main gatedriver 404 and/or the compensation gate driver 406 to turn the mainswitch 408 and/or the compensation switch 410 on or off (e.g., to openor close the main switch 408 and/or the compensation switch 410)according to switch timings described herein (e.g., with respect to FIG.7 and/or the like).

As shown in FIG. 4B, the process of example implementation 450 mayinclude the controller 402 performing delay tuning for the controlsignal provided to the main gate driver 404 of the main switch 408. Asdescribed herein with respect to FIG. 1A, the timing of the main switch130 and the compensation switch 114 may be controlled such that thecompensation electrical pulse is discharged during a discharge time thatat least partially overlaps with a time interval during which the mainelectrical pulse is generated. When the controller 402 performs delaytuning, the controller 402 may adjust the control signal provided to themain gate driver 404 of the main switch 408 such that the compensationelectrical pulse is discharged during a discharge time that at leastpartially overlaps with a time interval during which the main electricalpulse is generated. For example, and as further described with respectto FIG. 7, the controller 402 may perform delay tuning to adjust a timeinterval between when the compensation switch 410 transitions from aclosed state to an open state (e.g., to generate the compensationelectrical pulse) and when the main switch 408 transitions from an openstate to a closed state (e.g., to generate the main electrical pulse).

As also shown in FIG. 4B, the process of example implementation 450 mayinclude the controller 402 performing pulse width tuning for the controlsignal provided to the compensation gate driver 406 of the compensationswitch 410. As described herein with respect to FIG. 1A, when thecompensation switch 114 is in the closed state, current may flow throughthe compensation circuit (e.g., via the charging circuit path 102) andcharge, during a charging time, the compensation inductive element 112,and when the compensation switch 114 transitions from the closed stateto the open state, current may discharge from the compensation inductiveelement 112 (e.g., via the discharging circuit path 104) to generate thecompensation electrical pulse to drive the compensation section 118 toemit the compensation optical pulse. Additionally, or alternatively, asdescribed herein with respect to FIG. 1B, when the compensation switch164 is in the closed state, current may flow through the compensationcircuit (e.g., via the compensation circuit path 154) to generate thecompensation electrical pulse to drive the compensation section 168 toemit the compensation optical pulse. In some implementations, a longercharging time may generate a wider pulse width for the compensationelectrical pulse and/or the compensation optical pulse than a pulsewidth achieved with a shorter charging time. Thus, an amount of timewhen the compensation switch 410 is in a closed state may be adjusted totune a pulse width of the compensation electrical pulse and/or thecompensation optical pulse. In some implementations, when the controller402 performs pulse width tuning, the controller 402 may adjust thecontrol signal provided to the compensation gate driver 406 of thecompensation switch 410 such that the compensation switch 410 is in theclosed state for a duration of time that achieves a pulse width for thecompensation optical pulse that corresponds to a rise time of the mainoptical pulse.

Furthermore, tuning the pulse width of the compensation electrical pulsemay adjust a fall time of the compensation electrical pulse and/or thecompensation optical pulse. Accordingly, the time that the compensationswitch 410 is in the closed state may be adjusted to tune the fall timeof the compensation electrical pulse and/or the compensation opticalpulse. Thus, in some implementations, the controller 402 may performpulse width tuning such that a fall time of the compensation opticalpulse corresponds to a rise time of the main optical pulse. For example,when the controller 402 performs pulse width tuning, the controller 402may adjust the control signal provided to the compensation gate driver406 of the compensation switch 410 such that the compensation switch 410is in the closed state for a duration of time that achieves a fall timeof the compensation optical pulse that corresponds to a rise time of themain optical pulse.

As indicated above, FIGS. 4A and 4B are provided merely as examples.Other examples may differ from what is described with regard to FIGS. 4Aand 4B.

FIG. 5 is a diagram of an example graph 500 (e.g., that may be obtainedfrom an oscilloscope) plotting voltages from an optical detectorreceiving an optical signal associated with an example implementation ofan electrical drive circuit and optical load described herein. Forexample, the electrical drive circuit and optical load may be similar tothe electrical drive circuits and the optical loads described hereinwith respect to FIGS. 1A, 2, and/or 3. The example graph 500 plots anoptical signal (e.g., an optical pulse, a compensation optical pulse,and/or the like) generated by an AC-coupled compensation section of aVCSEL array in response to electrical signals provided, by theelectrical drive circuit, to the AC-coupled compensation section, wherethe electrical signals correspond to a compensation electrical pulsesimilar to the compensation electrical pulses described herein withrespect to FIGS. 1A, 2, 3, 4A, and/or 4B.

As shown in FIG. 5, the optical pulse (e.g., a compensation opticalpulse) has a short rise time (e.g., a fast rise time). As noted herein,short rise times may facilitate achievement of a rectangular-shapedoptical pulse. Additionally, and as also shown in FIG. 5, the opticalpulse has a narrow width and a fall time, which, in someimplementations, may be tuned to compensate for a rise time of a mainoptical pulse as described herein.

FIG. 6 is a diagram of an example graph 600 (e.g., that may be obtainedfrom an oscilloscope) plotting voltages from an optical detectorreceiving an optical signal associated with an example implementation ofan electrical drive circuit and optical load described herein. Forexample, the electrical drive circuit and optical load may be similar tothe electrical drive circuits and the optical loads described hereinwith respect to FIGS. 1A, 1B, 2, and/or 3. The example graph 600 plotsan optical signal (e.g., of a series of optical pulses, main opticalpulses, and/or the like) generated by a DC-coupled main section of aVCSEL array in response to electrical signals provided, by theelectrical drive circuit, to the DC-coupled main section, where theelectrical signals correspond to a series of main electrical pulsessimilar to the main electrical pulses described herein with respect toFIGS. 1A, 1B, 2, 3, 4A, and/or 4B.

As shown in FIG. 6, the optical pulses (e.g., main optical pulses) ofthe optical signal have a long rise time (e.g., due to parasiticinductance), which distorts a shape of the optical pulses away from arectangular shape. Additionally, and as also shown in FIG. 6, theoptical pulses have a short fall time (e.g., a fast fall time), wherepower of the optical pulse is falling from peak power to zero. As notedherein, short fall times may facilitate achievement of arectangular-shaped optical pulse.

In FIGS. 5-6, limitations on measurement equipment (e.g. bandwidthlimitations on oscilloscopes, parasitic aspects of a probe, EMI(electromagnetic interference) from a high speed switching FET (fieldeffect transistor), and/or the like) may inhibit clean and accuratemeasurements of sub-nanosecond or picosecond electrical pulses directlyfrom the electrical drive circuit. Accordingly, simulations may be usedto estimate peak current provided by an electrical drive circuit to anoptical load.

As indicated above, FIGS. 5-6 are provided merely as examples. Otherexamples may differ from what is described with regard to FIGS. 5-6.

FIG. 7 is a diagram of example graphs 702, 704, 706, and 708 plottingswitch timing in an example implementation 700 of an electrical drivecircuit and a multi-section optical load (example graph 702), opticalpower of a section of the multi-section optical load in the exampleimplementation (example graph 704), optical power of another section ofthe multi-section optical load in the example implementation (examplegraph 706), and optical power of the multi-section optical load in theexample implementation as seen by a sensor (example graph 708).

Example graph 702 plots switch timing of a main switch (e.g., the mainswitch 130 of FIG. 1A, the main switch 230 of FIG. 2, the main switch330 of FIG. 3, and/or the like) and a compensation switch (e.g., thecompensation switch 114 of FIG. 1A, the compensation switch 214 of FIG.2, the compensation switch 314 of FIG. 3, and/or the like). As shown inFIG. 7, the main switch and the compensation switch may initially be off(e.g., in an open state), and, at a time t1, the compensation switch mayturn on (e.g., transition from the open state to a closed state).

As further shown in FIG. 7 by example graph 702, the compensation switchmay remain on (e.g., in the closed state) for a time interval Δt. Insome implementations, the time interval Δt may correspond to a chargingtime as described herein with respect to FIGS. 1A, 2, 3, 4A, and/or 4B.For example, during the time interval Δt, an electrical drive circuitmay cause current to charge one or more inductive elements (e.g.,through a charging circuit path). Alternatively, in the case of thecircuit(s) shown in FIG. 1B, the compensation switch 164 and the mainswitch 180 may have the same timing to produce a short pulse at a muchlower current.

As shown in FIG. 7 by example graph 702, the compensation switch mayturn off (e.g., transition from a closed state to an open state) at atime t2. In some implementations, when the compensation switch turnsoff, one or more inductive elements may discharge to provide acompensation electrical pulse to drive a compensation section of anoptical load to emit a compensation optical pulse as described hereinwith respect to FIGS. 1A, 2, 3, 4A, and/or 4B.

As further shown in FIG. 7 by example graph 702, the main switch mayturn on (e.g., transition from the open state to a closed state) at atime t3. In some implementations, when the main switch turns on, theelectrical drive circuit may generate a main electrical pulse to drive amain section of an optical load to emit a main optical pulse asdescribed herein with respect to FIGS. 1A, 1B, 2, 3, 4A, and/or 4B.Additionally, or alternatively, and as shown in FIG. 7 by example graph702, the main switch may remain on (e.g., in the closed state) for amain time interval and then turn off. In some implementations, the timet2 and the time t3 may be a same time. In some implementations, the timet2 may occur after the time t3.

Example graph 704 plots optical power of a main section (e.g., LD2) ofthe multi-section optical load. As shown in FIG. 7 by example graph 704,the optical power of the main section may begin increasing at the timet3 when the main switch turns on, and the rise time of the optical powermay be long, which distorts a shape of a main optical pulse, emitted bythe main section, away from a rectangular shape. As also shown in FIG. 7by example graph 704, the optical power of the main section may have ashort fall time (e.g., a fast fall time).

Example graph 706 plots optical power of a compensation section (e.g.,LD1) of the multi-section optical load. As shown in FIG. 7 by examplegraph 706, at time t1 when the compensation switch turns on (e.g.,transitions from the open state to a closed state), the optical power ofthe compensation section may be zero (e.g., because the compensationswitch shorts current from a source to ground). In some implementations,at time t1 when the compensation switch turns on, current may increaseand pass through the compensation switch and one or more inductiveelements during the time interval Δt.

As shown in FIG. 7 by example graph 706, at time t2 when thecompensation switch turns off (e.g., transitions from the closed stateto the open state), the optical power of the compensation section maynot immediately increase. In some implementations, at time t2 when thecompensation switch turns off, the optical power of the compensationsection may not immediately increase because there may be a short delay(e.g., two nanoseconds or less, one nanosecond or less, 0.5 nanosecondsor less, and/or the like) between time t2 and a time when a compensationelectrical pulse is generated (e.g., by discharging one or moreinductive elements) to drive the compensation section to emit acompensation optical pulse).

Additionally, or alternatively, the time t2 and the time t3 may becontrolled, adjusted, and/or the like (e.g., by a controller performingdelay tuning as noted with respect to FIGS. 4A and 4B) to account forthe short delay such that, as shown in example graph 706, the opticalpower of the compensation section may increase to a peak power at thetime t3 when the main switch turns on (e.g., transitions from the openstate to a closed state). In some implementations, the time t2 and thetime t3 may be controlled, adjusted, and/or the like (e.g., by acontroller performing delay tuning as noted with respect to FIGS. 4A and4B) based on a pulse width of the compensation electrical pulse and/orthe compensation optical pulse, control signal propagation delays (e.g.,from the controller to the gate drivers and/or the like), and/or thelike. However, as noted above, the time t2 and the time t3 may be a sametime, in some implementations.

As further shown in FIG. 7 by example graph 706, the optical power ofthe compensation section may have a short rise time, and, after reachingpeak power, may slowly decrease to zero and, therefore, have a long falltime. For example, one or more inductive elements discharging current toprovide the compensation electrical pulse to the compensation sectionmay increase the optical power of the compensation section and, as thecurrent discharged by the one or more inductive elements decreases, theoptical power of the compensation section may decrease to zero.

Example graph 708 plots optical power of the multi-section optical load,including the main section and the compensation section, as seen by asensor. As shown in FIG. 7 by example graph 708, the optical power ofthe multi-section optical load as seen by the sensor may at time t3increase quickly to peak power and, therefore, have a short rise time.As also shown in FIG. 7 by example graph 708, the optical power of themulti-section optical load as seen by the sensor may quickly decreasefrom peak power to zero and, therefore, have a short fall time. Asfurther shown in FIG. 7 by example graph 708, the optical power of themulti-section optical load as seen by the sensor may have a constantamplitude (e.g., low rippling) between the rise time and the fall time.In this regard, the optical power of the multi-section optical load asseen by the sensor has a rectangular shape, which may improveperformance of a time-of-flight-based measurement system.

As also shown in FIG. 7 by the dashed lines in example graph 708, theoptical power of the multi-section optical load as seen by the sensormay correspond to a sum of the optical power of the main section (e.g.,as shown in example graph 704) and the optical power of the compensationsection (e.g., as shown in example graph 706). In some implementations,the optical power of the compensation section, when emitting acompensation optical pulse, may compensate for the optical power of themain section, when emitting a main optical pulse, such that the opticalpower of the multi-section optical load as seen by the sensor (e.g., acombined optical pulse emitted by the multi-section optical load) has arectangular shape. For example, and as shown in FIG. 7 by example graphs704, 706, and 708, the short rise time of the compensation optical pulsemay compensate for the long rise time of the main optical pulse.Additionally, or alternatively, and as shown in FIG. 7 by example graphs704, 706, and 708, the fall time of the compensation optical pulse maycorrespond to the rise time of the main optical pulse (e.g., such thatthe compensation optical pulse compensates for the main optical pulseduring the long rise time of the main optical pulse).

In some implementations, a controller may control an electrical drivecircuit (e.g., including a charging circuit path, a discharging circuitpath, and a main circuit path) based on the switch timing of examplegraph 702 of FIG. 7. For example, the controller may control, based onthe switch timing of example graph 702 of FIG. 7, the electrical drivecircuit to provide the compensation electrical pulse to the compensationsection and provide the main electrical pulse to the main section togenerate a single combined optical pulse. Additionally, oralternatively, the controller may control the electrical drive circuit,based on the switch timing of example graph 702, to repeatedly, at apulse frequency, provide the compensation electrical pulse to thecompensation section and provide the main electrical pulse to the mainsection. For example, the pulse frequency may be in a range from 20megahertz (MHz) to 200 MHz. In some implementations, specifications ofswitches, one or more controllers, one or more FETs, one or more gatedrivers, and/or the like may limit the range of the pulse frequency(e.g., rather than other components and/or elements of the electricaldrive circuit).

As indicated above, FIG. 7 is provided merely as an example. Otherexamples may differ from what is described with regard to FIG. 7.

FIGS. 8A and 8B are diagrams of example graphs 802 and 804 plottingshapes of optical power of a section (e.g., LD1) of a multi-sectionoptical load in example implementations described herein. For example,the example graphs 802 and 804 may plot shapes of optical power of acompensation section driven by an electrical drive circuit as describedherein with respect to FIGS. 1A, 1B, 2, and/or 3.

As shown in FIG. 8A by example graph 802, a compensation width (e.g., awidth of a compensation optical pulse) may be adjusted to achievecompensation widths a, b, and c. For example, a capacitance of acompensation capacitive element (e.g., the compensation capacitiveelement 110 of FIG. 1A, the compensation capacitive element 160 of FIG.1B, and/or the like), in the electrical drive circuit, may be adjustedto achieve different compensation widths. In some implementations, ahigher capacitance may increase the compensation width, such as forcompensation width c. Additionally, or alternatively, a lowercapacitance may decrease the compensation width, such as forcompensation width a. In some implementations, by adjusting thecapacitance of the compensation capacitive element, the electrical drivecircuit may generate a compensation electrical pulse to drive thecompensation section to emit a compensation optical pulse havingdifferent compensation widths.

As shown in FIG. 8B and by example graph 804, a compensation strength(e.g., a maximum optical power and/or a fall time of a compensationoptical pulse) may be adjusted to achieve compensation strengths a, b,and c. For example, a voltage supplied by a source (e.g., thecompensation source 108 of FIG. 1A, the compensation source 158 of FIG.1B, and/or the like) and/or an inductance of an inductive element (e.g.,the compensation inductive element 112 of FIG. 1A, the compensationinductive element 212 of FIG. 2, and/or the like), in the electricaldrive circuit, may be adjusted to achieve different compensationstrengths. In some implementations, a higher voltage and/or a higherinductance may increase the compensation strength, such as forcompensation strength c. Additionally, or alternatively, a lower voltageand/or a lower inductance may decrease the compensation strength, suchas for compensation strength a. In some implementations, by adjustingthe voltage supplied by the source and/or the inductance of theinductive element, the electrical drive circuit may generate acompensation electrical pulse to drive the compensation section to emita compensation optical pulse having different compensation strengths.

By adjusting compensation width and adjusting compensation strength, theelectrical drive circuit may achieve a compensation optical pulse thatcompensates (e.g., complements) a main optical pulse to achieve acombined optical pulse having a rectangular shape. In this way, theelectrical drive circuit may be designed to provide a compensationelectrical pulse to drive a compensation section to emit a compensationoptical pulse and to provide a main electrical pulse to drive a mainsection to emit a main optical pulse, such that a combined optical pulse(e.g., emitted by a multi-section optical load including thecompensation section and the main section) has a rectangular shape.Furthermore, by driving the multi-section optical load to emit arectangular-shaped optical pulse, the electrical drive circuit mayimprove performance of a time-of-flight-based measurement system.

As indicated above, FIGS. 8A and 8B are provided merely as examples.Other examples may differ from what is described with regard to FIGS. 8Aand 8B.

FIGS. 9A and 9B are diagrams of example graphs 902 and 904 (e.g., thatmay be obtained from an oscilloscope) plotting voltages from an opticaldetector receiving optical signals associated with exampleimplementations of electrical drive circuits and optical loads describedherein. For example, the example graphs 902 and 904 may plot shapes ofoptical signals associated with a compensation section driven by anelectrical drive circuit as described herein with respect to FIGS. 1A,1B, 2, and/or 3.

As shown in FIGS. 9A and 9B, a compensation width (e.g., a width of acompensation optical pulse) may be adjusted to achieve differentcompensation widths. For example, a capacitance of a compensationcapacitive element (e.g., the compensation capacitive element 110 ofFIG. 1A, the compensation capacitive element 160 of FIG. 1B, and/or thelike), in the electrical drive circuit, may be adjusted to achievedifferent compensation widths. In some implementations, an electricaldrive circuit driving a compensation section to emit the compensationoptical pulse shown in FIG. 9A may include a compensation capacitiveelement having a capacitance that is lower than a capacitance of anothercompensation capacitive element included in another electrical drivecircuit driving a compensation section to emit the compensation opticalpulse shown in FIG. 9B. In other words, for a compensation capacitiveelement in an electrical drive circuit, a lower capacitance may resultin a narrower compensation width as shown in FIG. 9A, and a highercapacitance may result in a wider compensation width as shown in FIG.9B.

As indicated above, FIGS. 9A and 9B are provided merely as examples.Other examples may differ from what is described with regard to FIGS. 9Aand 9B.

FIGS. 10A, 10B, 10C, and 10D are diagrams of example implementations1002, 1004, 1006, 1008 of a multi-section optical load described herein.For example, the multi-section optical loads of example implementations1002, 1004, 1006, 1008 may be similar to the multi-section optical load140 of FIG. 1A, the multi-section optical load 190 of FIG. 1B, themulti-section optical load 240 of FIG. 2, the multi-section optical load340 of FIG. 3, and/or the like.

As shown in FIG. 10A, the multi-section optical load may be a singleVCSEL array die (e.g., a die including an array of VCSELs) including twosections, section 1 and section 2, where each section includes a set ofVCSELs of the array. In some implementations, section 1 and section 2may be a compensation section and a main section, respectively, asdescribed herein with respect to FIGS. 1A, 1B, 2, and/or 3. In someimplementations, section 1 and section 2 may include a same quantity ofVCSELs or different quantities of VCSELs (e.g., as shown in FIG. 10A).Additionally, or alternatively, and as shown in FIG. 10A, section 1 andsection 2 may be adjacent to each other on the VCSEL array die.

As shown in FIG. 10B, the multi-section optical load may be a singleVCSEL array die (e.g., a die including an array of VCSELs) including twosections, section 1 and section 2, where the sections are interleaved onthe single VCSEL array die. In some implementations, section 1 andsection 2 may be a compensation section and a main section,respectively, as described herein with respect to FIGS. 1A, 1B, 2,and/or 3. In some implementations, section 1 and section 2 may include afirst set of VCSELs and a second set of VCSELs, respectively, whereinthe first set of VCSELs are interspersed within the second set ofVCSELs. For example, and as shown in FIG. 10B, the first set of VCSELsof section 1 and the second set of VCSELs of section 2 may bealternating rows of VCSELs on the VCSEL array die.

As shown in FIG. 10C, the multi-section optical load may be a package ofVCSEL array dies including two VCSEL array dies, die 1 and die 2. Insome implementations, die 1 and die 2 may be a compensation section anda main section, respectively, as described herein with respect to FIGS.1A, 1B, 2, and/or 3.

As shown in FIG. 10D, the multi-section optical load may includedifferent sections with VCSELs arranged in an interspersed manner. Forexample, as shown in FIG. 10D, the VCSELs may be arranged in an array,and each VCSEL may included in one of multiple groups of VCSELs. Forexample, the VCSELs shown by black circles may be a first group ofVCSELs, the VCSELs shown by white circles may be a second group ofVCSELs, and the VCSELs shown by striped circles may be a third group ofVCSELs. The various groups of VCSELs may be interspersed, for example,to enable different groups of VCSELS to be independently addressed(e.g., during lasing operation). In some implementations, further detailrelating to the interspersed VCSEL array shown in FIG. 10D is providedin U.S. Patent Application Publication No. 2002/00119527, the contentsof which are hereby incorporated by reference.

As indicated above, FIGS. 10A, 10B, 10C, and 10D are provided merely asexamples. Other examples may differ from what is described with regardto FIGS. 10A, 10B, 10C, and 10D. For example, the multi-section opticalload may include more than two sections and/or dies (e.g., three, four,five, six, and/or the like). Additionally, or alternatively, VCSELs of asection may be arranged in any manner with respect to VCSELs of anothersection. In some implementations, VCSELs of a section may be positionedin a pattern (e.g., a regular pattern, a pseudo-random pattern, and/orthe like), a shape (e.g., a rectangle, a square, a circle, and/or thelike), and/or the like on a VCSEL array die, within a package, withrespect to VCSELs of another section, and/or the like. In someimplementations, the VCSELs of all sections of the multi-section opticalload may be configured to emit light at a same wavelength while theVCSELs from one section of the multi-section optical load may havedifferent structural features (e.g., a number of junctions, an opticalaperture size or shape, an oxidation trench size or shape, a pitchbetween emitters, an array layout, an operating current, and/or thelike) as compared with VCSELS from another section of the multi-sectionoptical load.

FIG. 11 is a diagram of an example optical output field of view of anexample implementation 1100 of an electrical drive circuit andmulti-section optical load as described herein. As shown in FIG. 11, anoptical device may include a multi-section optical load including acompensation section 1110 and a main section 1120. For example, themulti-section optical load, the compensation section 1110, and the mainsection 1120 may be similar to the multi-section optical load, thecompensation section, and the main section, respectively, as shown inand described herein with respect to FIGS. 1A, 1B, 2, and/or 3.Additionally, or alternatively, the multi-section optical load, thecompensation section 1110, and the main section 1120 may be driven by anelectrical drive circuit similar to the electrical drive circuits shownin and described herein with respect to FIGS. 1A, 1B, 2, and/or 3.

As shown in FIG. 11, the electrical drive circuit may drive thecompensation section 1110 to emit a compensation optical pulse having anoptical output field of view 1112, and may drive the main section 1120to emit a main optical pulse having an optical output field of view1122. In some implementations, and as shown in FIG. 11, the opticaldevice may include an optical element 1130, such as a diffuser, and theoptical element 1130 may mix light of the compensation optical pulsewith light of the main optical pulse such that the compensation section1110 and the main section 1120 have a same illumination region. Forexample, the compensation section 1110 and the main section 1120 may berelatively small as compared to the optical element 1130 such that, whenthe compensation section 1110 and the main section 1120 are positionednear each other, the optical element 1130 (e.g., a single opticalelement) may be positioned in the output field of view 1112 and theoutput field of view 1122 to mix light of the compensation optical pulsewith light of the main optical pulse.

In FIG. 11, the output field of view 1112 and the output field of view1122 above the optical element 1130 may appear to be offset from eachother. However, the offset is merely for illustrative purposes, and theoutput field of view 1112 and the output field of view 1122 above theoptical element 1130 may be substantially the same.

As indicated above, FIG. 11 is provided merely as an example. Otherexamples may differ from what is described with regard to FIG. 11. Forexample, in some implementations, the VCSELs of all sections of themulti-section optical load may be configured to emit light in the samefield of view.

FIG. 12 is a flow chart of an example process 1200 for driving amulti-section optical load. In some implementations, one or more processblocks of FIG. 12 may be performed by an optical device (e.g., anoptical device as shown in and described with respect to FIGS. 1A, 1B,2, 3, 4A, 4B, 7, 8A, 8B, 10A, 10B, 10C, and/or 11). In someimplementations, one or more process blocks of FIG. 12 may be performedby another device or a group of devices separate from or including theoptical device, such as an electrical drive circuit (e.g., an electricaldrive circuit as shown in and described with respect to FIGS. 1A, 1B, 2,3, 4A, 4B, 7, 8A, 8B, 10A, 10B, 10C, and/or 11), a time-of-flight-basedmeasurement system (e.g., a direct time-of-flight-based measurementsystem, an indirect time-of-flight-based measurement system, and/or thelike), a 3D sensing system, a LIDAR system, and/or the like.Additionally, or alternatively, one or more process blocks of FIG. 12may be performed by one or more components of an electrical drivecircuit, an optical device, a time-of-flight-based measurement system, a3D sensing system, a LIDAR system, and/or the like, such as a maincircuit path, a charging circuit path, a discharging circuit path, oneor more sources, one or more switches, a controller, and/or the like.

As shown in FIG. 12, process 1200 may include driving a compensationsection of a multi-section optical load to emit a compensation opticalpulse by providing, for a first time interval, a compensation electricalpulse to the compensation section (block 1210). For example, theelectrical drive circuit and/or the optical device including theelectrical drive circuit and the multi-section optical load may drive acompensation section of the multi-section optical load to emit acompensation optical pulse by, providing, for a first time interval, acompensation electrical pulse to the compensation section, as describedabove.

As further shown in FIG. 12, process 1200 may include driving a mainsection of the multi-section optical load to emit a main optical pulseby generating, for a second time interval, a main electrical pulse,wherein at least a portion of the first time interval overlaps with thesecond time interval, and providing the main electrical pulse to themain section (block 1220). For example, the electrical drive circuitand/or the optical device including the electrical drive circuit and themulti-section optical load may drive a main section of the multi-sectionoptical load to emit a main optical pulse by generating, for a secondtime interval, a main electrical pulse and providing the main electricalpulse to the main section, as described above. In some implementations,at least a portion of the first time interval overlaps with the secondtime interval.

As further shown in FIG. 12, process 1200 may include emitting acombined optical pulse, wherein the combined optical pulse includes thecompensation optical pulse and the main optical pulse, and wherein thecombined optical pulse has a shorter rise time than the main opticalpulse (block 1230). For example, the electrical drive circuit and/or theoptical device including the electrical drive circuit and themulti-section optical load may emit a combined optical pulse, asdescribed above. In some implementations, the combined optical pulseincludes the compensation optical pulse and the main optical pulse. Insome implementations, the combined optical pulse has a shorter rise timethan the main optical pulse.

Process 1200 may include additional implementations, such as any singleimplementation or any combination of implementations described belowand/or in connection with one or more other processes describedelsewhere herein.

In a first implementation, the main optical pulse has a longer rise timeas compared to the compensation optical pulse, and a shorter rise timeof the compensation optical pulse compensates for the longer rise timeof the main optical pulse.

In a second implementation, alone or in combination with the firstimplementation, the first time interval begins at a same time as thesecond time interval.

In a third implementation, alone or in combination with one or more ofthe first and second implementations, the first time interval beginsbefore the second time interval.

In a fourth implementation, alone or in combination with one or more ofthe first through third implementations, the first time interval is lessthan half the second time interval.

In a fifth implementation, alone or in combination with one or more ofthe first through fourth implementations, driving the compensationsection of the multi-section optical load to emit the compensationoptical pulse may include charging one or more inductive elements, anddischarging, after the charging and for the first time interval, the oneor more inductive elements to provide the compensation electrical pulseto the compensation section, and driving the main section of themulti-section optical load may include generating the main electricalpulse after the charging.

In a fifth implementation, alone or in combination with one or more ofthe first through fourth implementations, the electrical drive circuitand/or the optical device includes a charging circuit path for chargingthe one or more inductive elements, and a discharging circuit path fordischarging the compensation electrical pulse.

In a sixth implementation, alone or in combination with one or more ofthe first through fifth implementations, charging the one or moreinductive elements comprises closing a switch in the electrical drivecircuit for a charging time, and discharging the one or more inductiveelements to provide the compensation electrical pulse comprises opening,after the charging time, the switch.

In a seventh implementation, alone or in combination with one or more ofthe first through sixth implementations, the multi-section optical loadis a vertical-cavity surface-emitting laser (VCSEL) array die, and eachof the compensation section and the main section is a section of theVCSEL array die.

In an eighth implementation, alone or in combination with one or more ofthe first through seventh implementations, the multi-section opticalload is a package of VCSEL array dies, and each of the compensationsection and the main section is a VCSEL array die of the package.

Although FIG. 12 shows example blocks of process 1200, in someimplementations, process 1200 may include additional blocks, fewerblocks, different blocks, or differently arranged blocks than thosedepicted in FIG. 12. Additionally, or alternatively, two or more of theblocks of process 1200 may be performed in parallel.

The foregoing disclosure provides illustration and description, but isnot intended to be exhaustive or to limit the implementations to theprecise form disclosed. Modifications and variations may be made inlight of the above disclosure or may be acquired from practice of theimplementations. Furthermore, any of the implementations describedherein may be combined unless the foregoing disclosure expresslyprovides a reason that one or more implementations may not be combined.

As used herein, the terms circuit, integrated circuit, chip, chipset,die, semiconductor device, electronic device, and/or the like areintended to be broadly construed as applicable to the variousimplementations described herein, as these terms can be usedinterchangeably in the field of electronics. With respect to a circuit,an integrated circuit, and/or the like, power, ground, and varioussignals may be coupled between and among circuit elements (e.g.,resistors, inductors, capacitors, transistors, and/or the like) viaphysical, electrically conductive connections. Such a point ofconnection may be referred to as an input, output, input/output (I/O),terminal, line, pin, pad, port, interface, or similar variants andcombinations. Although connections between and among circuits can bemade by way of electrical conductors, circuits and other circuitelements may additionally, or alternatively, be coupled by way ofoptical, mechanical, magnetic, electrostatic, electromagnetic, and/orother suitable interfaces.

It will be apparent that systems and/or methods described herein may beimplemented in different forms of hardware, software, circuitry, or acombination thereof. The actual specialized control hardware, softwarecode, or circuitry used to implement these systems and/or methods is notlimiting of the implementations. Thus, the operation and behavior of thesystems and/or methods are described herein without reference tospecific software code—it being understood that software and hardware(e.g., integrated circuits) can be designed to implement the systemsand/or methods based on the description herein.

Even though particular combinations of features are recited in theclaims and/or disclosed in the specification, these combinations are notintended to limit the disclosure of various implementations. In fact,many of these features may be combined in ways not specifically recitedin the claims and/or disclosed in the specification. Although eachdependent claim listed below may directly depend on only one claim, thedisclosure of various implementations includes each dependent claim incombination with every other claim in the claim set.

No element, act, or instruction used herein should be construed ascritical or essential unless explicitly described as such. Also, as usedherein, the articles “a” and “an” are intended to include one or moreitems, and may be used interchangeably with “one or more.” Further, asused herein, the article “the” is intended to include one or more itemsreferenced in connection with the article “the” and may be usedinterchangeably with “the one or more.” Furthermore, as used herein, theterm “set” is intended to include one or more items (e.g., relateditems, unrelated items, a combination of related and unrelated items,etc.), and may be used interchangeably with “one or more.” Where onlyone item is intended, the phrase “only one” or similar language is used.Also, as used herein, the terms “has,” “have,” “having,” or the like areintended to be open-ended terms. Further, the phrase “based on” isintended to mean “based, at least in part, on” unless explicitly statedotherwise. Also, as used herein, the term “or” is intended to beinclusive when used in a series and may be used interchangeably with“and/or,” unless explicitly stated otherwise (e.g., if used incombination with “either” or “only one of”).

Further, spatially relative terms, such as “below,” “lower,” “above,”“upper,” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. The spatially relative termsare intended to encompass different orientations of the apparatus,device, and/or element in use or operation in addition to theorientation depicted in the figures. The apparatus may be otherwiseoriented (rotated 90 degrees or at other orientations) and the spatiallyrelative descriptors used herein may likewise be interpretedaccordingly.

What is claimed is:
 1. A method for driving a multi-section opticalload, the method comprising: driving, by an electrical drive circuit, acompensation section of the multi-section optical load to emit acompensation optical pulse by: providing, for a first time interval, acompensation electrical pulse to the compensation section; driving, bythe electrical drive circuit, a main section of the multi-sectionoptical load to emit a main optical pulse by: generating, for a secondtime interval, a main electrical pulse, wherein at least a portion ofthe first time interval overlaps with the second time interval, whereinthe compensation section and the main section are electrically separatesections of the multi-section optical load, and providing the mainelectrical pulse to the main section; and emitting, by an optical deviceincluding the electrical drive circuit and the multi-section opticalload, a combined optical pulse, wherein the combined optical pulseincludes the compensation optical pulse and the main optical pulse, andwherein the combined optical pulse has a shorter rise time than the mainoptical pulse.
 2. The method of claim 1, wherein the main optical pulsehas a longer rise time as compared to the compensation optical pulse,and wherein a shorter rise time of the compensation optical pulsecompensates for the longer rise time of the main optical pulse.
 3. Themethod of claim 1, wherein the first time interval begins at a same timeas the second time interval.
 4. The method of claim 1, wherein the firsttime interval begins before the second time interval.
 5. The method ofclaim 1, wherein the first time interval is less than half the secondtime interval.
 6. The method of claim 1, wherein driving thecompensation section of the multi-section optical load to emit thecompensation optical pulse includes: charging one or more inductiveelements, and discharging, after the charging and for the first timeinterval, the one or more inductive elements to provide the compensationelectrical pulse to the compensation section, and wherein driving themain section of the multi-section optical load includes generating themain electrical pulse after the charging.
 7. The method of claim 6,wherein the electrical drive circuit comprises: a charging circuit pathfor charging the one or more inductive elements; and a dischargingcircuit path for discharging the compensation electrical pulse.
 8. Themethod of claim 6, wherein charging the one or more inductive elementscomprises closing a switch in the electrical drive circuit for acharging time, and discharging the one or more inductive elements toprovide the compensation electrical pulse comprises opening, after thecharging time, the switch.
 9. The method of claim 1, wherein themulti-section optical load is a vertical-cavity surface-emitting laser(VCSEL) array die, and each of the compensation section and the mainsection is a section of the VCSEL array die.
 10. The method of claim 1,wherein the multi-section optical load is a package of vertical-cavitysurface-emitting laser (VCSEL) array dies, and each of the compensationsection and the main section is a VCSEL array die of the package.
 11. Anelectrical drive circuit for driving a multi-section optical load, theelectrical drive circuit comprising: a charging circuit path forcharging, during a charging time, one or more inductive elements; adischarging circuit path for generating, during a first time intervalafter the charging time, a compensation electrical pulse by dischargingthe one or more inductive elements; a main circuit path for generating,during a second time interval, a main electrical pulse, wherein at leasta portion of the first time interval overlaps with the second timeinterval; and wherein the electrical drive circuit is to: provide acompensation electrical pulse to a compensation section of themulti-section optical load, and provide a main electrical pulse to amain section of the multi-section optical load; and wherein thecompensation electrical pulse and the main electrical pulse are providedto the multi-section optical load via independent circuit paths.
 12. Theelectrical drive circuit of claim 11, wherein the charging circuit pathcomprises: the one or more inductive elements; a capacitive element toconnect in parallel to a source; and a switch having an open state and aclosed state, wherein the switch being in the closed state, during thecharging time, is to cause current to charge the one or more inductiveelements and the capacitive element through the charging circuit path.13. The electrical drive circuit of claim 12, wherein the dischargingcircuit path comprises: the one or more inductive elements; and thecapacitive element; and wherein the switch transitioning from the closedstate to the open state is to cause the one or more inductive elementsto discharge current, during the first time interval, through thedischarging circuit path to generate the compensation electrical pulse.14. The electrical drive circuit of claim 11, wherein the chargingcircuit path, the main circuit path, and the discharging circuit pathare to connect to a single source.
 15. The electrical drive circuit ofclaim 11, wherein the one or more inductive elements comprise a tracehaving a length and a width to achieve, for the discharging circuitpath, a total inductance such that the compensation optical pulse has awidth and/or an amplitude that compensates the main optical pulse. 16.An optical device, comprising: one or more sources; a multi-sectionoptical load to emit light, wherein the multi-section optical loadincludes a compensation section and a main section, and wherein thecompensation section is electrically separated from the main sectionwithin the multi-section optical load; a compensation circuit forgenerating a compensation electrical pulse and providing thecompensation electrical pulse to the compensation section; a maincircuit for generating a main electrical pulse and providing the mainelectrical pulse to the main section; and a controller to control thecompensation circuit and the main circuit by: causing the compensationcircuit to generate the compensation electrical pulse for a first timeinterval, and causing the main circuit to generate the main electricalpulse for a second time interval, wherein at least a portion of thefirst time interval overlaps with the second time interval; and whereinthe compensation section is to emit, in response to the compensationelectrical pulse, a compensation optical pulse; wherein the main sectionis to emit, in response to the main electrical pulse, a main opticalpulse; wherein a combined optical pulse includes the compensationoptical pulse and the main optical pulse; and wherein the combinedoptical pulse has a shorter rise time than the main optical pulse. 17.The optical device of claim 16, wherein the multi-section optical loadis a vertical-cavity surface-emitting laser (VCSEL) array die, and eachof the compensation section and the main section is a section of theVCSEL array die.
 18. The optical device of claim 16, wherein themulti-section optical load is a package of vertical-cavitysurface-emitting laser (VCSEL) array dies, and each of the compensationsection and the main section is a VCSEL array die of the package. 19.The optical device of claim 16, wherein the compensation section and themain section are interleaved.
 20. The optical device of claim 16,wherein the compensation optical pulse has a rise time of less than 100picoseconds.
 21. The optical device of claim 16, wherein the mainoptical pulse has a longer rise time as compared to the compensationoptical pulse, and wherein the compensation optical pulse compensatesfor the longer rise time of the main optical pulse.
 22. The opticaldevice of claim 16, wherein the combined optical pulse has a shorterfall time than the compensation optical pulse.
 23. The optical device ofclaim 16, wherein the controller is to control the compensation circuitand the main circuit to repeatedly, at a pulse frequency, provide thecompensation electrical pulse to the compensation section and providethe main electrical pulse to the main section.
 24. The optical device ofclaim 23, wherein the pulse frequency is in a range from 20 megahertz to200 megahertz.
 25. The optical device of claim 16, wherein thecompensation circuit includes a charging circuit path and a dischargingcircuit path, and wherein the charging circuit path includes acompensation inductive element.